DOI: 10.1038/ngeo2786
论文题名: No evidence for Hadean continental crust within Earth's oldest evolved rock unit
作者: Reimink J.R. ; Davies J.H.F.L. ; Chacko T. ; Stern R.A. ; Heaman L.M. ; Sarkar C. ; Schaltegger U. ; Creaser R.A. ; Pearson D.G.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2016
卷: 9, 期: 10 起始页码: 777
结束页码: 780
语种: 英语
Scopus关键词: continental crust
; geochemical method
; gneiss
; Hadean
; hafnium
; isotopic analysis
; lead isotope
; oceanic crust
; planetary evolution
; uranium isotope
; zircon
; Canada
; Acasta
英文摘要: Due to the acute scarcity of very ancient rocks, the composition of Earth's embryonic crust during the Hadean eon (>4.0 billion years ago) is a critical unknown in our search to understand how the earliest continents evolved. Whether the Hadean Earth was dominated by mafic-composition crust, similar to today's oceanic crust, or included significant amounts of continental crust remains an unsolved question that carries major implications for the earliest atmosphere, the origin of life, and the geochemical evolution of the crust-mantle system. Here we present new U-Pb and Hf isotope data on zircons from the only precisely dated Hadean rock unit on Earth - a 4,019.6 ± 1.8 Myr tonalitic gneiss unit in the Acasta Gneiss Complex, Canada. Combined zircon and whole-rock geochemical data from this ancient unit shows no indication of derivation from, or interaction with, older Hadean continental crust. Instead, the data provide the first direct evidence that the oldest known evolved crust on Earth was generated from an older ultramafic or mafic reservoir that probably surfaced the early Earth. © 2016 Macmillan Publishers Limited, part of Springer Nature. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105917
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, Canada; Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC, United States; Department of Earth Sciences, University of Geneva, Geneva, Switzerland
Recommended Citation:
Reimink J.R.,Davies J.H.F.L.,Chacko T.,et al. No evidence for Hadean continental crust within Earth's oldest evolved rock unit[J]. Nature Geoscience,2016-01-01,9(10)